I would think a major issue is that it requires a bit of confidence submitting a competition entry if one hasn't done so before, and then fear the risk of having to judge a set of others' efforts without feeling qualified to do so.

I've looked back at some of the weekly comps circa 2010 and around 20 entries each week seemed to be the norm then too.
Anyone who gives up entering due to lack of entries is perpetuating the problem!
I suggested a reader vote system late last year but it wasn't commented on further:
https://www.pentaxuser.com/forum/topic/judging-57058/p-0#comm596336
I suppose it would need to be determined who could take part in the judging, just other entrants or anyone. I can visualise a sort of Eurovision clique going on, I'll vote for yours if you vote for mine!
Further to my 2016 comment, it seems one person can increment the like count by repeatedly clicking on it!

For me they don't even have to be moving!
I must say the 150-450 has done well, I'm pretty sure you could recognise the RA pilot if you knew them. Surprised he didn't give you a wave!

No comparison to mine for the day!

Great shots.. sort of disproves that oft stated comment here that photos are fast moving objects can't be captured in focus on a Pentax so me must go to where the grass is greener.
I photographed the red arrows that day from my back garden (there's one taken for the monthly comp.)

People in the EU aren't aware of that!

Also, is it a camera problem or user problem. I'm certain some people must hold the camera steadier than others, if one has a 'tripod' steady grip (when hand holding) then the SR presumably isn't necessary!
If one's doing a backwards somersault at the time of taking the photo SR may be pretty handy.
If the SR matches actual hand held shake, it should also recognise when the camera is steady enough not to need correction, i.e. when the camera is on a tripod or other steady surface. Guess this applies to all SR systems.

will6558, the photos in your gallery taken with the K-3 & 16-45 look pretty sharp to me. What are you viewing them on?

The A 24mm isn't bad at all and if need be crop the image. I crop 90% of my images as invariably the edges have unwanted detail or there's too much bland sky.
To save missing things set the lens to its hyperfocal setting. With the A24 That means setting the focus and aperture to the red distance (7ft/2.2m) & aperture (f/11) markings and you should be good to go for most things instantly. Useful for street photography to take a photo from the waist without the subject being aware and with a 24mm you'll have space to crop to straighten it up in PP.